It is common for people to be exposed to various types of radiation. Often excessive exposure to radiation can be hazardous to one's health. One type of radiation that frequently raises a health concern is ultraviolet (UV) radiation. UV radiation is subdivided into three types: UV-A, UV-B, and UV-C. UV-C radiation has wavelengths in the range of 200 to 285 nanometers (nm) and is totally absorbed by the earth's atmosphere. UV-B, from about 285 to 318 nm, is known to cause skin cancer in humans. UV-A, from about 315 to 400 nm, is mostly responsible for tanning. However, UV-A has also been found to play some role in skin cancer and is the cause of eye cataracts, solar retinitis, and corneal dystrophies.
Although several UV radiation measuring and warning instruments have been developed and made commercially available, these instruments are disadvantageous for various reasons. One disadvantage is that the instruments are often a stand alone, special purpose device. As a result, a user must separately wear the special purpose device, which can be intrusive and often inconvenient. Another disadvantage is that those instruments, even if separate but attachable to other devices, hinder or impede the design for the devices. Thus, there is a need for improved approaches to measure and inform persons of UV radiation levels.